Please put this sentence into simpler words. What does it mean, exactly? I believe I know what it means but would like confirmation.

"Oliver had been too often subjected to the process to which the very expressive monosyllable just recorded bears reference, to entertain the smallest doubt that the owner of the voice, who he might be, would redeem his pledge, most honourably."

Oliver was familiar with the process that the word mentioned in the sentence refers to. He was sure that whoever spoke the word would keep their promise.